WriteStreamComp:
PRIVATE
PROC [comp: Composite, class: Classification, makeStream:
BOOL, f:
IO.
STREAM, indent:
NAT] = {
RayCast is about to return class. Write the name of comp and summarize the classification.
if not makeStream then do nothing
opname: Rope.ROPE;
IF NOT makeStream THEN RETURN;
Indent[f, indent];
SELECT comp.operation
FROM
union => opname ← "union";
intersection => opname ← "intersection";
difference => opname ← "difference";
ENDCASE => ERROR;
f.PutF["Composite %g [op: %g] returns class: [count: %g]\n",[rope[comp.name]],[rope[opname]], [integer[class.count]]];
WritePrimNames[class, f, indent];
}; -- end of WriteStreamComp
Indent:
PRIVATE
PROC [f:
IO.
STREAM, indent:
NAT] = {
FOR i:
NAT
IN[1..indent]
DO
f.PutChar[IO.TAB];
ENDLOOP;
};
WritePrimNames:
PRIVATE
PROC [class: Classification, f:
IO.
STREAM, indent:
NAT] = {
FOR i:
NAT
IN[1..class.count]
DO
Indent[f, indent+1];
f.PutF["%g) %g at t = %g\n", [integer[i]], [rope[class.primitives[i].name]],
[real[class.params[i]]]];
ENDLOOP;
}; -- end of WritePrimNames
WriteStreamPrim:
PRIVATE
PROC [prim: Primitive, class: Classification, makeStream:
BOOL, f:
IO.
STREAM, indent:
NAT] = {
IF NOT makeStream THEN RETURN;
Indent[f, indent];
f.PutF["Primitive %g returns class: [count: %g]\n", [rope[prim.name]], [integer[class.count]]];
WriteParams[class, f, indent];
}; -- end of WriteStreamPrim
WriteParams:
PRIVATE
PROC [class: Classification, f:
IO.
STREAM, indent:
NAT] = {
FOR i:
NAT
IN[1..class.count]
DO
Indent[f, indent+1];
f.PutF["%g) %g at t = %g\n", [integer[i]], [rope[class.primitives[i].name]],
[real[class.params[i]]]];
ENDLOOP;
}; -- end of WritePrimNames
RayCast:
PUBLIC
PROC [cameraPoint: Point2d, sceneRay: Ray, node:
REF
ANY, makeStream:
BOOL ←
FALSE, f:
IO.
STREAM ←
NIL, indent:
NAT ← 0]
RETURNS [class: Classification] = {
The main ray casting procedure. Scene Ray must be in WORLD coordinates before this procedure is called.
IF node = NIL THEN {class ← EmptyClass[]; RETURN};
WITH node SELECT FROM
comp: Composite => {
leftClass, rightClass: Classification;
leftBoxHit, leftHit, rightBoxHit, rightHit: BOOL;
totalMiss: BOOL ← FALSE;
boundBox: BoundBox;
Before casting each ray, see if the ray will be in the bounding box of the son node.
For optimizing, here is the plan:
1) Check ray for left bound box. Set leftBoxHit if appropriate.
2) If leftBoxHit then cast the ray. Set leftHit if appropriate.
3) If not leftHit then if comp.operation = intersection or difference, return miss.
4) If hit, or union, then right box test. Set RightBoxMiss if appropriate.
5) If miss then return: leftclass for difference, empty for intersection, leftClass for union.
6) Else cast ray.
7) Return rightclass or combination if appropriate
1) Check ray for left bound box. Set leftBoxHit if appropriate.
WITH comp.leftSolid
SELECT
FROM
p: Primitive => boundBox ← p.boundBox;
c: Composite => boundBox ← c.boundBox;
ENDCASE => ERROR;
leftBoxHit ← SVBoundBox.PointInBoundBox[cameraPoint, boundBox];
2) If leftBoxHit then cast the ray. Set leftHit if appropriate.
IF leftBoxHit
THEN {
leftClass ← RayCast[cameraPoint, sceneRay, comp.leftSolid, makeStream, f, indent];
leftHit ← (leftClass.count > 0) }
ELSE {leftHit ← FALSE; leftClass ← EmptyClass[]};
3) If not leftHit then if comp.operation = intersection or difference, return miss.
IF NOT leftHit THEN IF comp.operation = intersection OR comp.operation = difference
THEN {
class ← leftClass; WriteStreamComp[comp, class, makeStream, f, indent]; RETURN};
leftClass is (or is equivalent to) EmptyClass[];
4) If hit, or union, then right box test. Set RightBoxMiss if appropriate. (we don't have to test for this state. It is the only one left.)
WITH comp.rightSolid
SELECT
FROM
p: Primitive => boundBox ← p.boundBox;
c: Composite => boundBox ← c.boundBox;
ENDCASE => ERROR;
rightBoxHit ← SVBoundBox.PointInBoundBox[cameraPoint, boundBox];
5) If miss then return EmptyClass. Else cast ray.
IF NOT rightBoxHit THEN
This could be a union with or without a left miss or (intersection/difference) with an initial hit.
SELECT comp.operation
FROM
union => {class ← leftClass; WriteStreamComp[comp, class, makeStream, f, indent]; RETURN};
intersection =>
IF NOT leftHit THEN RETURN[leftClass]
ELSE {
ReturnClassToPool[leftClass]; class ← EmptyClass[]; WriteStreamComp[comp, class, makeStream, f, indent]; RETURN};
difference => {class ← leftClass; WriteStreamComp[comp, class, makeStream, f, indent]; RETURN};
ENDCASE => ERROR;
6) Else cast ray. We have Union, or (intersection/difference) with left hit. Ray hits box.
rightClass ← RayCast[cameraPoint, sceneRay, comp.rightSolid, makeStream, f, indent];
rightHit ← rightClass.count > 0;
7) Return rightclass, combination or empty if appropriate
SELECT comp.operation
FROM
union =>
IF rightHit
THEN {
IF leftHit THEN class ← UnionCombine[leftClass, rightClass]
ELSE {ReturnClassToPool[leftClass]; class ← rightClass}
}
ELSE {
ReturnClassToPool[rightClass]; class ← leftClass};
intersection =>
IF rightHit
THEN {
IF leftHit THEN class ← IntersectionCombine[leftClass, rightClass]
ELSE {ReturnClassToPool[rightClass]; class ← leftClass;}
}
ELSE
IF leftHit
THEN {ReturnClassToPool[leftClass]; class ← rightClass}
ELSE {ReturnClassToPool[rightClass]; class ← leftClass};
difference =>
IF rightHit
THEN {
IF leftHit THEN class ← DifferenceCombine[leftClass, rightClass]
ELSE {ReturnClassToPool[rightClass]; class ← leftClass} -- leftClass null
}
ELSE {ReturnClassToPool[rightClass]; class ← leftClass};
ENDCASE => ERROR;
WriteStreamComp[comp, class, makeStream, f, indent];
RETURN};
prim: Primitive => {
localRay: Ray;
One optimation: each primitive will keep track of the last ray that hit it, and the vector corresponding to a unit x step in the CAMERA coord sys. The ray will contain information about whether or not it is the first ray of a new line.
localRay ← TransformRay[sceneRay, prim.worldWRTPrim]; -- (takes a new ray from the pool)
class ← prim.rayCast[cameraPoint, localRay, prim.mo, prim];
WriteStreamPrim[prim, class, makeStream, f, 0];
ReturnRayToPool[localRay]; -- returns ray to pool
RETURN};
ENDCASE => ERROR;
}; -- end of RayCast
RayCastNoBBoxes:
PUBLIC
PROC [sceneRay: Ray, node:
REF
ANY, makeStream:
BOOL ←
FALSE, f:
IO.
STREAM ←
NIL, indent:
NAT ← 0]
RETURNS [class: Classification] = {
Ignore any bounding boxes which were computed. This is useful if the ray does not originate from the screen (as for computing shadows). Of course, bounding spheres would be useful in this case.
The main ray casting procedure. Scene Ray must be in WORLD coordinates before this procedure is called.
IF node = NIL THEN {class ← EmptyClass[]; RETURN};
WITH node SELECT FROM
comp: Composite => {
leftClass, rightClass: Classification;
leftHit, rightHit: BOOL;
totalMiss: BOOL ← FALSE;
For optimizing, here is the plan:
1) Cast the left ray. Set leftHit if appropriate.
2) If not leftHit then if comp.operation = intersection or difference, return miss.
3) If hit, or union, then cast right ray.
4) Return rightclass or combination if appropriate
1) Cast the left ray. Set leftHit if appropriate.
leftClass ← RayCastNoBBoxes[sceneRay, comp.leftSolid, makeStream, f, indent];
leftHit ← (leftClass.count > 0);
2) If not leftHit then if comp.operation = intersection or difference, return miss.
IF NOT leftHit THEN IF comp.operation = intersection OR comp.operation = difference
THEN {
class ← leftClass; WriteStreamComp[comp, class, makeStream, f, indent]; RETURN};
leftClass is (or is equivalent to) EmptyClass[];
3) If hit, or union, then cast right ray.
rightClass ← RayCastNoBBoxes[sceneRay, comp.rightSolid, makeStream, f, indent];
rightHit ← rightClass.count > 0;
4) Return rightclass, combination or empty if appropriate
SELECT comp.operation
FROM
union =>
IF rightHit
THEN {
IF leftHit THEN class ← UnionCombine[leftClass, rightClass]
ELSE {ReturnClassToPool[leftClass]; class ← rightClass}
}
ELSE {
ReturnClassToPool[rightClass]; class ← leftClass};
intersection =>
IF rightHit
THEN {
IF leftHit THEN class ← IntersectionCombine[leftClass, rightClass]
ELSE {ReturnClassToPool[rightClass]; class ← leftClass;}
}
ELSE
IF leftHit
THEN {ReturnClassToPool[leftClass]; class ← rightClass}
ELSE {ReturnClassToPool[rightClass]; class ← leftClass};
difference =>
IF rightHit
THEN {
IF leftHit THEN class ← DifferenceCombine[leftClass, rightClass]
ELSE {ReturnClassToPool[rightClass]; class ← leftClass} -- leftClass null
}
ELSE {ReturnClassToPool[rightClass]; class ← leftClass};
ENDCASE => ERROR;
WriteStreamComp[comp, class, makeStream, f, indent];
RETURN};
prim: Primitive => {
localRay: Ray;
One optimation: each primitive will keep track of the last ray that hit it, and the vector corresponding to a unit x step in the CAMERA coord sys. The ray will contain information about whether or not it is the first ray of a new line.
localRay ← TransformRay[sceneRay, prim.worldWRTPrim]; -- (takes a new ray from the pool)
class ← prim.rayCastNoBBoxes[localRay, prim.mo, prim];
WriteStreamPrim[prim, class, makeStream, f, 0];
ReturnRayToPool[localRay]; -- returns ray to pool
RETURN};
ENDCASE => ERROR;
}; -- end of RayCastNoBboxes
HitsTree:
PUBLIC
PROC [worldRay: Ray, tree: CSGTree]
RETURNS [
BOOL] = {
node: REF ANY ← tree.son;
class: Classification;
hits: BOOL;
class ← RayCastNoBBoxes [sceneRay: worldRay, node: node, makeStream: FALSE];
hits ← class.count > 0;
ReturnClassToPool[class];
RETURN[hits];
};
EmptyClass:
PRIVATE
PROC
RETURNS [class: Classification] = {
class ← GetClassFromPool[];
class.count ← 0;
class.classifs[1] ← FALSE;
}; -- end of EmptyClass
TransformRay:
PROC [ray: Ray, mat: Matrix4by4]
RETURNS [newRay: Ray] = {
newRay ← GetRayFromPool[];
newRay.basePt ← Matrix3d.Update[mat, ray.basePt];
newRay.direction ← Matrix3d.UpdateVectorEvenScaling[mat, ray.direction];
}; -- end of TransformRay
AddRay:
PROC [ray1, ray2: Ray] = {
-- puts sum in ray2
ray2.basePt ← SVVector3d.Add[ray1.basePt, ray2.basePt];
ray2.direction ← SVVector3d.Add[ray1.direction, ray2.direction];
}; -- end of AddRay
SubtractRays:
PROC [ray1, ray2: Ray]
RETURNS [ray1MinusRay2: Ray] = {
-- puts sum in ray2
ray1MinusRay2 ← NEW[RayObj];
ray1MinusRay2.basePt ← SVVector3d.Difference[ray1.basePt, ray2.basePt];
ray1MinusRay2.direction ← SVVector3d.Difference[ray1.direction, ray2.direction];
}; -- end of AddRay
Each primitive shape must have a procedure here which can classify a ray with respect to it.
Combine:
PUBLIC
PROC [leftClass, rightClass: Classification, op: PointSetOp]
RETURNS [combinedClass: Classification] = {
SELECT op
FROM
union => combinedClass ← UnionCombine[leftClass, rightClass];
intersection => combinedClass ← IntersectionCombine[leftClass, rightClass];
difference => combinedClass ← DifferenceCombine[leftClass, rightClass];
ENDCASE => ERROR;
};
SceneExceedsMaximumDepth: SIGNAL = CODE;
UnionCombine:
PROC [leftClass, rightClass: Classification]
RETURNS [combinedClass: Classification] = {
Merge the two sorted lists together classifying the segments by the OR of the Classifs for each segment
lPtr, rPtr: NAT;
combinedClass ← GetClassFromPool[];
lPtr ← rPtr ← 1;
combinedClass.count ← leftClass.count + rightClass.count;
IF combinedClass.count > CSG.maxSceneDepth THEN SIGNAL SceneExceedsMaximumDepth;
FOR i:
NAT
IN[1..combinedClass.count]
DO
IF rPtr > rightClass.count THEN GOTO RPtrWentOver;
IF lPtr > leftClass.count THEN GOTO LPtrWentOver;
IF leftClass.params[lPtr] < rightClass.params[rPtr]
THEN {
combinedClass.normals[i] ← leftClass.normals[lPtr];
combinedClass.params[i] ← leftClass.params[lPtr];
combinedClass.surfaces[i] ← leftClass.surfaces[lPtr];
combinedClass.primitives[i] ← leftClass.primitives[lPtr];
combinedClass.classifs[i] ← leftClass.classifs[lPtr] OR rightClass.classifs[rPtr];
lPtr ← lPtr + 1;
}
ELSE {
combinedClass.normals[i] ← rightClass.normals[rPtr];
combinedClass.params[i] ← rightClass.params[rPtr];
combinedClass.surfaces[i] ← rightClass.surfaces[rPtr];
combinedClass.primitives[i] ← rightClass.primitives[rPtr];
combinedClass.classifs[i] ← leftClass.classifs[lPtr] OR rightClass.classifs[rPtr];
rPtr ← rPtr + 1;
};
REPEAT
RPtrWentOver => { -- finish up with lPtr data
FOR k:
NAT ← i, k+1
UNTIL k > combinedClass.count
DO
combinedClass.normals[k] ← leftClass.normals[lPtr];
combinedClass.params[k] ← leftClass.params[lPtr];
combinedClass.surfaces[k] ← leftClass.surfaces[lPtr];
combinedClass.primitives[k] ← leftClass.primitives[lPtr];
combinedClass.classifs[k] ← leftClass.classifs[lPtr] OR rightClass.classifs[rPtr];
lPtr ← lPtr + 1;
ENDLOOP};
LPtrWentOver => { -- finish up with rPtr data
FOR k:
NAT ← i, k+1
UNTIL k > combinedClass.count
DO
combinedClass.normals[k] ← rightClass.normals[rPtr];
combinedClass.params[k] ← rightClass.params[rPtr];
combinedClass.surfaces[k] ← rightClass.surfaces[rPtr];
combinedClass.primitives[k] ← rightClass.primitives[rPtr];
combinedClass.classifs[k] ← leftClass.classifs[lPtr] OR rightClass.classifs[rPtr];
rPtr ← rPtr + 1;
ENDLOOP};
ENDLOOP;
combinedClass.classifs[combinedClass.count+1] ← leftClass.classifs[lPtr] OR rightClass.classifs[rPtr];
ReturnClassToPool[leftClass];
ReturnClassToPool[rightClass];
}; -- end of UnionCombine
IntersectionCombine:
PROC [leftClass, rightClass: Classification]
RETURNS [combinedClass: Classification] = {
Merge the two sorted lists together classifying the segments by the AND of the Classifs for each segment
lPtr, rPtr: NAT;
combinedClass ← GetClassFromPool[];
lPtr ← rPtr ← 1;
combinedClass.count ← leftClass.count + rightClass.count;
IF combinedClass.count > CSG.maxSceneDepth THEN SIGNAL SceneExceedsMaximumDepth;
FOR i:
NAT
IN[1..combinedClass.count]
DO
IF rPtr > rightClass.count THEN GOTO RPtrWentOver;
IF lPtr > leftClass.count THEN GOTO LPtrWentOver;
IF leftClass.params[lPtr] < rightClass.params[rPtr]
THEN {
combinedClass.normals[i] ← leftClass.normals[lPtr];
combinedClass.params[i] ← leftClass.params[lPtr];
combinedClass.surfaces[i] ← leftClass.surfaces[lPtr];
combinedClass.primitives[i] ← leftClass.primitives[lPtr];
combinedClass.classifs[i] ← leftClass.classifs[lPtr] AND rightClass.classifs[rPtr];
lPtr ← lPtr + 1;
}
ELSE {
combinedClass.normals[i] ← rightClass.normals[rPtr];
combinedClass.params[i] ← rightClass.params[rPtr];
combinedClass.surfaces[i] ← rightClass.surfaces[rPtr];
combinedClass.primitives[i] ← rightClass.primitives[rPtr];
combinedClass.classifs[i] ← leftClass.classifs[lPtr] AND rightClass.classifs[rPtr];
rPtr ← rPtr + 1;
};
REPEAT
RPtrWentOver => { -- finish up with lPtr data
FOR k:
NAT ← i, k+1
UNTIL k > combinedClass.count
DO
combinedClass.normals[k] ← leftClass.normals[lPtr];
combinedClass.params[k] ← leftClass.params[lPtr];
combinedClass.surfaces[k] ← leftClass.surfaces[lPtr];
combinedClass.primitives[k] ← leftClass.primitives[lPtr];
combinedClass.classifs[k] ← leftClass.classifs[lPtr] AND rightClass.classifs[rPtr];
lPtr ← lPtr + 1;
ENDLOOP};
LPtrWentOver => { -- finish up with rPtr data
FOR k:
NAT ← i, k+1
UNTIL k > combinedClass.count
DO
combinedClass.normals[k] ← rightClass.normals[rPtr];
combinedClass.params[k] ← rightClass.params[rPtr];
combinedClass.surfaces[k] ← rightClass.surfaces[rPtr];
combinedClass.primitives[k] ← rightClass.primitives[rPtr];
combinedClass.classifs[k] ← leftClass.classifs[lPtr] AND rightClass.classifs[rPtr];
rPtr ← rPtr + 1;
ENDLOOP};
ENDLOOP;
combinedClass.classifs[combinedClass.count+1] ← leftClass.classifs[lPtr] AND rightClass.classifs[rPtr];
ConsolidateClassification[combinedClass];
ReturnClassToPool[leftClass];
ReturnClassToPool[rightClass];
}; -- end of IntersectionCombine
ConsolidateClassification:
PROC [class: Classification] = {
Combine adjacent regions which have the same classif and throw out the surface and parameter information at those points
recall ClassificationObj is RECORD [count, params, surfaces, classifs, topNormal];
currentlyWorkingOn: BOOL;
compact: CompactArray ← GetCompactFromPool[];
IF class.classifs[1] # FALSE THEN SIGNAL RayClassBeginsWithTrue;
currentlyWorkingOn ← class.classifs[1];
FOR i:
NAT
IN[2..class.count+1]
DO
IF class.classifs[i] = currentlyWorkingOn
THEN
-- this is not a transition so throw it out
compact[i-1] ← FALSE -- don't keep it
ELSE {compact[i-1] ← TRUE; currentlyWorkingOn ← class.classifs[i];};
ENDLOOP;
IF class.classifs[class.count+1] # FALSE THEN SIGNAL RayClassEndsWithTrue;
CompactClassification[class, compact];
ReturnCompactToPool[compact];
}; -- end of ConsolidateClassification
RayClassEndsWithTrue: SIGNAL = CODE;
RayClassBeginsWithTrue: SIGNAL = CODE;
CompactClassification:
PROC [class: Classification, compact: CompactArray] = {
Compact[i] is TRUE if we should keep class.*[i], FALSE otherwise. Order is preserved among the items we keep
newCount: NAT;
newCount ← 0;
FOR i:
NAT
IN[1..class.count]
DO
IF compact[i] THEN {newCount ← newCount + 1;
class.params[newCount] ← class.params[i];
class.classifs[newCount] ← class.classifs[i];
class.normals[newCount] ← class.normals[i];
class.surfaces[newCount] ← class.surfaces[i];
class.primitives[newCount] ← class.primitives[i];};
ENDLOOP;
class.classifs[newCount+1] ← class.classifs[class.count+1];
The in-out value on the far side of the last param that changed in-out will always be the last value given in the class.
class.count ← newCount;
};
DifferenceCombine:
PROC [leftClass, rightClass: Classification]
RETURNS [combinedClass: Classification] = {
Merge the two sorted lists together classifying the segments by the (left AND NOT right) of the Classifs for each segment
lPtr, rPtr: NAT;
combinedClass ← GetClassFromPool[];
IF combinedClass.count > CSG.maxSceneDepth THEN SIGNAL SceneExceedsMaximumDepth;
lPtr ← rPtr ← 1;
combinedClass.count ← leftClass.count + rightClass.count;
FOR i:
NAT
IN[1..combinedClass.count]
DO
IF rPtr > rightClass.count THEN GOTO RPtrWentOver;
IF lPtr > leftClass.count THEN GOTO LPtrWentOver;
IF leftClass.params[lPtr] < rightClass.params[rPtr]
THEN {
combinedClass.normals[i] ← leftClass.normals[lPtr];
combinedClass.params[i] ← leftClass.params[lPtr];
combinedClass.surfaces[i] ← leftClass.surfaces[lPtr];
combinedClass.primitives[i] ← leftClass.primitives[lPtr];
combinedClass.classifs[i] ← leftClass.classifs[lPtr] AND NOT rightClass.classifs[rPtr];
lPtr ← lPtr + 1;
}
ELSE {
combinedClass.normals[i] ← SVVector3d.Negate[rightClass.normals[rPtr]];
combinedClass.params[i] ← rightClass.params[rPtr];
combinedClass.surfaces[i] ← rightClass.surfaces[rPtr];
combinedClass.primitives[i] ← rightClass.primitives[rPtr];
combinedClass.classifs[i] ← leftClass.classifs[lPtr] AND NOT rightClass.classifs[rPtr];
rPtr ← rPtr + 1;
};
REPEAT
RPtrWentOver => { -- finish up with lPtr data
FOR k:
NAT ← i, k+1
UNTIL k > combinedClass.count
DO
combinedClass.normals[k] ← leftClass.normals[lPtr];
combinedClass.params[k] ← leftClass.params[lPtr];
combinedClass.surfaces[k] ← leftClass.surfaces[lPtr];
combinedClass.primitives[k] ← leftClass.primitives[lPtr];
combinedClass.classifs[k] ← leftClass.classifs[lPtr] AND NOT rightClass.classifs[rPtr];
lPtr ← lPtr + 1;
ENDLOOP};
LPtrWentOver => { -- finish up with rPtr data
FOR k:
NAT ← i, k+1
UNTIL k > combinedClass.count
DO
combinedClass.normals[k] ← SVVector3d.Negate[rightClass.normals[rPtr]];
combinedClass.params[k] ← rightClass.params[rPtr];
combinedClass.surfaces[k] ← rightClass.surfaces[rPtr];
combinedClass.primitives[k] ← rightClass.primitives[rPtr];
combinedClass.classifs[k] ← leftClass.classifs[lPtr] AND NOT rightClass.classifs[rPtr];
rPtr ← rPtr + 1;
ENDLOOP};
ENDLOOP;
combinedClass.classifs[combinedClass.count+1] ← leftClass.classifs[lPtr] AND NOT rightClass.classifs[rPtr];
ConsolidateClassification[combinedClass];
ReturnClassToPool[leftClass];
ReturnClassToPool[rightClass];
}; -- end of DifferenceCombine
SingleRay:
PUBLIC
PROC [x, y:
INTEGER, tree: CSGTree, lightSources: LightSourceList, camera: Camera, makeStream:
BOOL ←
FALSE, f:
IO.
STREAM ←
NIL]
RETURNS [color: Color] = {
cameraRay, worldRay: Ray;
cameraWRTWorld: Matrix3d.Matrix4by4;
boundBox: BoundBox;
cameraRay ← NEW[RayObj];
boundBox ← Preprocess3d.Preprocess[tree, camera]; -- must call this before casting rays
cameraRay.basePt ← [x,y,0]; cameraRay.direction ← [x,y,-camera.focalLength];
ray with respect to Camera (perspective)
find WORLD ray
cameraWRTWorld ← CoordSys.FindInTermsOfWorld[camera.coordSys];
worldRay ← TransformRay[cameraRay, cameraWRTWorld]; -- alocates ray from pool
IF makeStream THEN f.PutChar[IO.CR];
color ← TopColorCast[[x,y], worldRay, tree, lightSources, camera, boundBox, makeStream, f, 0];
ReturnRayToPool[worldRay];
}; -- end of SingleRay
SingleRay2:
PUBLIC
PROC [cameraPoint: Point2d, tree: CSGTree, lightSources: LightSourceList, camera: Camera, makeStream:
BOOL ←
FALSE, f:
IO.
STREAM ←
NIL]
RETURNS [class: Classification] = {
The client must be sure to call ReturnClassToPool[class] when he is done with it.
topNode: REF ANY ← tree.son;
cameraRay, worldRay: Ray;
cameraWRTWorld: Matrix4by4 ← CoordSys.FindInTermsOfWorld[camera.coordSys];
focalLength: REAL ← - camera.focalLength;
cameraRay ← NEW[RayObj];
cameraRay.basePt ← [cameraPoint[1], cameraPoint[2], 0];
cameraRay.direction ← [cameraPoint[1], cameraPoint[2], focalLength];
worldRay ← TransformRay[cameraRay, cameraWRTWorld]; -- allocates ray from pool
class ← RayCast[cameraPoint, worldRay, topNode, makeStream, f, 0];
ReturnRayToPool[worldRay];
}; -- end of SingleRay2
NodeToRope:
PROC [node:
REF
ANY, depth:
NAT]
RETURNS [r: Rope.
ROPE] = {
IF node = NIL THEN RETURN[NIL];
WITH node
SELECT
FROM
prim: Primitive => {r ← prim.name; RETURN};
comp: Composite => {r ← comp.name;
IF depth < 2 THEN RETURN
ELSE {r1: Rope.ROPE;
r2: Rope.ROPE;
leftSon: REF ANY ← comp.leftSolid;
rightSon: REF ANY ← comp.rightSolid;
r1 ← NodeToRope[leftSon, depth - 1];
r2 ← NodeToRope[rightSon, depth - 1];
r ← Rope.Cat[r,": ",r1,"/",r2];
RETURN};
};
ENDCASE => ERROR;
}; -- end of NodeToRope
OutputTreeInfo:
PRIVATE
PROC [node:
REF
ANY,
I: Image, outStream:
IO.
STREAM] = {
debugName, debugRope: Rope.ROPE; -- ****
debugStream: IO.STREAM;
debugStream ← IO.CreateOutputStreamToRope[];
debugName ← NodeToRope[node, 2];
debugStream.PutF["About to Draw Tree: %g (%g by %g)...", [rope[debugName]], [integer[I.bwWindow.fref.raster.scanCount]], [integer[I.bwWindow.fref.raster.scanLength]]];
outStream.PutF["About to Draw Tree: %g (%g by %g)...", [rope[debugName]], [integer[I.bwWindow.fref.raster.scanCount]], [integer[I.bwWindow.fref.raster.scanLength]]];
debugRope ← debugStream.GetOutputStreamRope[];
MessageWindow.Append[debugRope, TRUE];
MessageWindow.Blink[];
}; -- end of OutputTreeInfo
GetXStepRayInWorld:
PRIVATE
PROC [stepSize:
REAL, focalLength:
REAL, cameraWRTWorld: Matrix4by4]
RETURNS [ray: Ray] = {
cameraXStepRay1, cameraXStepRay2: Ray;
cameraXStepRay1InWorld, cameraXStepRay2InWorld: Ray;
cameraXStepRay1 ← NEW[RayObj ← [[0,0,0], [0,0, focalLength]]];
cameraXStepRay2 ← NEW[RayObj ← [[stepSize,0,0], [stepSize,0, focalLength]]];
cameraXStepRay1InWorld ← TransformRay[cameraXStepRay1, cameraWRTWorld];
cameraXStepRay2InWorld ← TransformRay[cameraXStepRay2, cameraWRTWorld];
ray ← SubtractRays[cameraXStepRay2InWorld, cameraXStepRay1InWorld];
ReturnRayToPool[cameraXStepRay1InWorld];
ReturnRayToPool[cameraXStepRay2InWorld];
}; -- end of GetXStepRayInWorld
MasterObjectColorFromPrimitive:
PRIVATE
PROC [primitive: Primitive, t:
REAL, sceneRay: Ray, primitiveNormal: Vector]
RETURNS [color: Color] = {
scalars: Vector;
localRay: Ray;
point3d: Point3d;
x, y, z: REAL;
IF primitive.artwork.source =
NIL
THEN {
-- pure color artwork
color ← primitive.artwork.color;
}
ELSE {
scalars ← primitive.scalars;
localRay ← TransformRay[sceneRay, primitive.worldWRTPrim];
x ← localRay.basePt[1] + t*localRay.direction[1];
y ← localRay.basePt[2] + t*localRay.direction[2];
z ← localRay.basePt[3] + t*localRay.direction[3];
ReturnRayToPool[localRay];
point3d[1] ← scalars[1]*x;
point3d[2] ← scalars[2]*y;
point3d[3] ← scalars[3]*z;
color ← SVArtwork.FindColorAtSurfacePoint[primitive.artwork, point3d, primitiveNormal];
};
};
ColorFromClass:
PRIVATE
PROC [class: Classification, x, y:
REAL, lightSources: LightSourceList, camera: Camera, sceneRay: Ray, tree: CSGTree]
RETURNS [color: Color] = {
We are given a classification, a list of lightsources, a camera, the screen point from which the ray was shot, and the ray in WORLD coordinates from which we can derive the eyepoint. To produce an image with shadows, we proceed as follows:
Make a new list of lightsources which includes only those lightsources visible from the surface point then proceed in the usual way.
surf: Surface;
surfColor: Color;
eyePoint: Point3d;
surfacePt: Point3d;
primitive: Primitive;
visibleLights: LightSourceList;
t: REAL;
worldNormal, primitiveNormal: Vector;
IF class.count = 0 THEN {color ← tree.backgroundColor; RETURN};
surf ← class.surfaces[1];
t ← class.params[1];-- the parameter of the ray intersection
primitiveNormal ← class.normals[1];
primitive ← class.primitives[1];
surfColor ← MasterObjectColorFromPrimitive[primitive, t, sceneRay, primitiveNormal];
worldNormal ← Matrix3d.UpdateVectorWithInverse[primitive.worldWRTPrim, primitiveNormal];
surfacePt[1] ← sceneRay.basePt[1] + t*sceneRay.direction[1];
surfacePt[2] ← sceneRay.basePt[2] + t*sceneRay.direction[2];
surfacePt[3] ← sceneRay.basePt[3] + t*sceneRay.direction[3];
eyePoint ← CSGGraphics.LocalToWorld[[0,0,camera.focalLength], camera.coordSys];
eyePoint ← SVVector3d.Difference[sceneRay.basePt, sceneRay.direction];
visibleLights ← IF tree.shadows THEN SVFancyRays.VisibleLights[lightSources, surfacePt, tree] ELSE lightSources;
Since sceneRay is in WORLD coordinates, this finds eyePoint in WORLD coordinates
SELECT primitive.artwork.material
FROM
chalk => color ← Shading.DiffuseReflectance[worldNormal, surfacePt, surfColor, visibleLights];
plastic => color ← Shading.DiffuseAndSpecularReflectance[eyePoint, worldNormal, surfacePt, surfColor, visibleLights];
ENDCASE => ERROR;
}; -- end of ColorFromClass
ScanLine: TYPE = REF ScanLineObj;
ScanLineObj: TYPE = RECORD [
seq: SEQUENCE lineLen: NAT OF Color];
CreateScanLine:
PRIVATE
PROC [len:
NAT]
RETURNS [scanLine: ScanLine] = {
scanLine ← NEW[ScanLineObj[len]];
};
CopyScanLine:
PRIVATE
PROC [from: ScanLine, to: ScanLine] = {
FOR i:
NAT
IN [0..to.lineLen)
DO
to[i] ← from[i];
ENDLOOP;
};
PutColorInScanLine:
PRIVATE
PROC [scanLine: ScanLine, index:
NAT, color: Color] = {
scanLine[index] ← color;
};
TopColorCast:
PRIVATE
PROC [cameraPoint: Point2d, sceneRay: Ray, tree: CSGTree, lightSources: LightSourceList, camera: Camera, sceneBox: BoundBox, makeStream:
BOOL ←
FALSE, f:
IO.
STREAM ←
NIL, indent:
NAT ← 0]
RETURNS [color: Color] = {
node: REF ANY ← tree.son;
class: Classification;
IF tree.son = NIL THEN RETURN[tree.backgroundColor];
IF SVBoundBox.PointInBoundBox[cameraPoint, sceneBox]
THEN {
finalClassCount, firstClassCount: NAT;
firstClassCount ← NumberOfClassesInPool[]; -- for debugging purposes.
class ← RayCast[cameraPoint, sceneRay, node, makeStream, f, indent];
color ← ColorFromClass[class, cameraPoint[1], cameraPoint[2], lightSources, camera, sceneRay, tree];
ReturnClassToPool[class];
finalClassCount ← NumberOfClassesInPool[]; -- for debugging purposes.
IF finalClassCount < firstClassCount
THEN {
f.PutF["WARNING: A Classification was lost while casting a ray at [%g, %g]", [real[cameraPoint[1]]], [real[cameraPoint[2]]]];
};
}
ELSE color ← tree.backgroundColor;
};
ColorCast:
PRIVATE
PROC [cameraPoint: Point2d, sceneRay: Ray, tree: CSGTree, lightSources: LightSourceList, camera: Camera, makeStream:
BOOL ←
FALSE, f:
IO.
STREAM ←
NIL, indent:
NAT ← 0]
RETURNS [color: Color] = {
class: Classification;
class ← RayCast[cameraPoint, sceneRay, tree.son, makeStream, f, indent];
color ← ColorFromClass[class, cameraPoint[1], cameraPoint[2], lightSources, camera, sceneRay, tree];
ReturnClassToPool[class];
};
SetUpRayTrace:
PROC [boundBox: BoundBox, camera: Camera, aisRope: Rope.
ROPE, bAndWOnly:
BOOL, resolution:
REAL, zone:
UNCOUNTED
ZONE, raster:
AIS.Raster, commentString:
LONG
STRING]
RETURNS [
I: Image, xSamples, ySamples:
NAT, stepSize, xStart, yStart:
REAL] = {
Look at the frame of the camera. If frame.fullscreen is TRUE then use the bounding box of the scene. If it is FALSE, then use the frame parameters to determine the bounding box of our ray tracing. In this case, we should check before casting each ray to see if it is in the scene's bounding box before casting it.
extentX, extentY, projectionX, projectionY, trueExtentX, trueExtentY: REAL;
comment: Rope.ROPE ← IO.PutFR["res: %g dpi", [real[resolution]]];
ConvertUnsafe.AppendRope[commentString, comment];
stepSize ← 72.0/resolution; -- in screen dots per sample
We know the size of the box which we wish to raycast and the resolution of the casting in samples per inch. Our box size is in screen dots (at 72 per inch). We wish to know screen dots per sample. (Extent/72)*resolution = inches*(samples per inch) = samples. Extent/samples = screen dots/sample as required. Compactly, then, we need 72/resolution screen dots per sample and Extent/(screen dots per sample) for total number of samples.
IF camera.frame.fullScreen
THEN {
[I, xSamples, ySamples] ← SVImage.OpenImage[aisRope, bAndWOnly, boundBox.minVert[1], boundBox.minVert[2], boundBox.maxVert[1], boundBox.maxVert[2], resolution, raster, commentString];
extentX ← boundBox.maxVert[1] - boundBox.minVert[1];
extentY ← boundBox.maxVert[2] - boundBox.minVert[2];
}
ELSE {
[I, xSamples, ySamples] ← SVImage.OpenImage[aisRope, bAndWOnly, camera.frame.downLeft[1], camera.frame.downLeft[2], camera.frame.upRight[1], camera.frame.upRight[2], resolution, raster, commentString];
extentX ← camera.frame.upRight[1] - camera.frame.downLeft[1];
extentY ← camera.frame.upRight[2] - camera.frame.downLeft[2];
};
Now for the hard part. boundBox tells us the outline of the initial box. trueExtentX represents the actual extent from the left of the first pixel to the right of the last pixel. Likewise for trueExtentY. We subtract the initial extent from the true extent and split the difference. Subtracting the result to the original bounding box origin gives the ray tracing grid outline.
trueExtentX ← Real.Float[xSamples-1]*stepSize;
trueExtentY ← Real.Float[ySamples-1]*stepSize;
projectionX ← (trueExtentX - extentX)/2.0;
projectionY ← (trueExtentY - extentY)/2.0;
IF camera.frame.fullScreen
THEN {
xStart ← boundBox.minVert[1] - projectionX;
yStart ← boundBox.minVert[2] - projectionY;
}
ELSE {
xStart ← camera.frame.downLeft[1] - projectionX;
yStart ← camera.frame.downLeft[2] - projectionY;
};
Now (xStart, yStart) is the center of the origin pixel. Subtracting another half a pixel will give us the lower left hand corner of the pixel.
xStart ← xStart - stepSize/2.0;
yStart ← yStart - stepSize/2.0;
}; -- end of SetUpRayTrace
ShutDownRayTrace:
PROC [aisRope: Rope.
ROPE, zone:
UNCOUNTED
ZONE, raster:
AIS.Raster,
I: Image] = {
SVImage.CloseImage[I, aisRope];
zone.FREE[@raster];
UnsafeStorage.FreeUZone[zone];
};
FillScanLine:
PROC [startX, stepSize:
REAL, xSamples:
NAT, y:
REAL, cameraXStepRayInWorld: Ray, worldRay: Ray, tree: CSGTree, lightSources: LightSourceList, camera: Camera, boundBox: BoundBox, scanLine: ScanLine, outStream:
IO.
STREAM] = {
Cast the first ray of the y scan line
color: Color;
thisX: REAL;
color ← TopColorCast[[startX, y], worldRay, tree, lightSources, camera, boundBox, FALSE, outStream];
PutColorInScanLine[scanLine, 0, color];
AddRay[cameraXStepRayInWorld, worldRay]; -- updates worldRay
FOR j:
INTEGER
IN[1..xSamples]
DO
-- left to right
thisX ← startX+Real.Float[j]*stepSize;
color ← TopColorCast[[thisX, y], worldRay, tree, lightSources, camera, boundBox];
PutColorInScanLine[scanLine, j, color];
AddRay[cameraXStepRayInWorld, worldRay]; -- updates worldRay
ENDLOOP;
};
DrawTree:
PUBLIC
PROC [dc: Graphics.Context, tree: CSGTree, lightSources: LightSourceList, camera: Camera, aisRope: Rope.
ROPE, bAndWOnly:
BOOL, resolution:
REAL, notify: NotifyOfProgressProc ← NoOpNotifyOfProgress, clientData:
REF
ANY ←
NIL, outStream:
IO.
STREAM] = {
topNode: REF ANY; -- tree.son. The top active node of the CSG Tree
I: Image; raster: AIS.Raster; zone: UNCOUNTED ZONE;
commentString: LONG STRING ← [256];
boundBox: BoundBox;
cameraWRTWorld: Matrix4by4;
cameraXStepRayInWorld, cameraRay, worldRay: Ray;
stepSize, xStart, yStart, thisY: REAL;
xSamples, ySamples: NAT;
interpreting results of the cast ray
focalLength: REAL; color: Color; scanLine1, scanLine2: ScanLine;
topNode ← tree.son;
camera.abort ← FALSE; -- if camera.abort becomes TRUE, close files and return.
zone ← UnsafeStorage.NewUZone[]; raster ← zone.NEW[AIS.RasterPart];
boundBox ← Preprocess3d.Preprocess[tree, camera]; -- must call this before casting rays
Calculates current transfrom matrices and bounding boxes.
[I, xSamples, ySamples, stepSize, xStart, yStart] ← SetUpRayTrace [boundBox, camera, aisRope, bAndWOnly, resolution, zone, raster, commentString];
OutputTreeInfo[topNode, I, outStream];
scanLine1 ← CreateScanLine[xSamples+1]; scanLine2 ← CreateScanLine[xSamples+1];
cameraWRTWorld ← CoordSys.FindInTermsOfWorld[camera.coordSys];
focalLength ← - camera.focalLength;
cameraRay ← NEW[RayObj]; -- DrawTree recycles its own ray
cameraXStepRayInWorld ← GetXStepRayInWorld[stepSize, focalLength, cameraWRTWorld];
cast the first scan line
cameraRay.basePt ← [xStart, yStart, 0]; cameraRay.direction ← [xStart, yStart, focalLength];
worldRay ← TransformRay[cameraRay, cameraWRTWorld]; -- allocates ray from pool
FillScanLine [xStart, stepSize, xSamples, yStart, cameraXStepRayInWorld, worldRay, tree, lightSources, camera, boundBox, scanLine1, outStream];
ReturnRayToPool[worldRay];
FOR i:
INTEGER
IN[1..ySamples]
DO
-- bottom to top
IF camera.abort =
TRUE
THEN {
SVImage.CloseImage[I, aisRope];
MessageWindow.Append["CastRays aborted. Partial files saved.", TRUE];
outStream.PutF["CastRays aborted. Partial files saved."];
RETURN;
};
notify[yStart+i*stepSize, xStart, yStart, xStart+xSamples*stepSize, yStart+ySamples*stepSize, clientData]; -- tell the user interface that we have just cast line i - 1.
thisY ← yStart+i*stepSize;
cameraRay.basePt ← [xStart, thisY, 0]; cameraRay.direction ← [xStart, thisY, focalLength];
worldRay ← TransformRay[cameraRay, cameraWRTWorld]; -- allocates ray from pool
FillScanLine [xStart, stepSize, xSamples, thisY, cameraXStepRayInWorld, worldRay, tree, lightSources, camera, boundBox, scanLine2, outStream];
ReturnRayToPool[worldRay];
we now have two complete scan lines. Average values in fours and write to ais.
FOR k:
NAT
IN[0..xSamples)
DO
IF MoreOrLessTheSame[scanLine1[k], scanLine1[k+1],
scanLine2[k], scanLine2[k+1]] THEN
color ← ColorAverage[scanLine1[k], scanLine1[k+1], scanLine2[k], scanLine2[k+1]];
SVImage.PutImage[I, i, k, color, xSamples, ySamples];
ENDLOOP;
CopyScanLine [scanLine2, scanLine1];
ENDLOOP;
ShutDownRayTrace[aisRope, zone, raster, I];
}; -- end of DrawTree
MoreOrLessTheSame:
PRIVATE
PROC [a, b, c, d:
REAL]
RETURNS [
BOOL] = {
min, max: REAL;
min ← max ← a;
IF b < min THEN min ← b ELSE IF b > max THEN max ← b;
IF c < min THEN min ← c ELSE IF c > max THEN max ← c;
IF d < min THEN min ← d ELSE IF d > max THEN max ← d;
IF max - min > 10 THEN RETURN[FALSE] ELSE RETURN[TRUE];
}; -- end of MoreOrLessTheSame
ColorAverage:
PRIVATE
PROC [a, b, c, d: Color]
RETURNS [avgColor: Color] = {
ar, ag, ab, br, bg, bb, cr, cg, cb, dr, dg, db, red, green, blue: REAL;
[ar, ag, ab] ← GraphicsColor.ColorToRGB[a];
[br, bg, bb] ← GraphicsColor.ColorToRGB[b];
[cr, cg, cb] ← GraphicsColor.ColorToRGB[c];
[dr, dg, db] ← GraphicsColor.ColorToRGB[d];
red ← (ar + br + cr + dr)/4.0;
green ← (ag + bg + cg + dg)/4.0;
blue ← (ab + bb + cb + db)/4.0;
avgColor ← GraphicsColor.RGBToColor[red, green, blue];
}; -- end of ColorAverage
ELSE color ← CastMoreRays[ul: scanLine1[k], ur: scanLine1[k+1], dl: scanLine2[k], dr: scanLine2[k+1], left: k, right: k+1, top: i, bottom: i-1, topNode: topNode, focalLength: focalLength, lightSources: lightSources, cameraWRTWorld: cameraWRTWorld];
CastMoreRays:
PRIVATE
PROC [ul, ur, dl, dr: Color, left, right, top, bottom:
REAL, tree: CSGTree, focalLength:
REAL, lightSources: LightSourceList, camera: Camera]
RETURNS [color: Color] = {
Cast rays left, right, top, bottom, and middle. Use rays ul, ur, dl, and dr. This further subdivides each square for a more accurate intensity value.
cameraRay: Ray ← GetRayFromPool[];
worldRay: Ray;
cameraWRTWorld: Matrix4by4 ← camera.coordSys.mat;
leftColor, rightColor, topColor, bottomColor, middleColor: Color;
midLeftY, midTopX: REAL;
midLeftY ← (top-bottom)/2.0;
midTopX ← (right-left)/2.0;
cameraRay.basePt ← [left, midLeftY, 0];cameraRay.direction ← [left, midLeftY, focalLength];
worldRay ← TransformRay[cameraRay, cameraWRTWorld]; -- allocates ray from pool
leftColor ← ColorCast[[left, midLeftY], worldRay, tree, lightSources, camera];
ReturnRayToPool[worldRay];
cameraRay.basePt ← [right, midLeftY, 0];cameraRay.direction ← [right, midLeftY, focalLength];
worldRay ← TransformRay[cameraRay, cameraWRTWorld]; -- allocates ray from pool
rightColor ← ColorCast[[right, midLeftY], worldRay, tree, lightSources, camera];
ReturnRayToPool[worldRay];
cameraRay.basePt ← [midTopX, top, 0];cameraRay.direction ← [midTopX, top, focalLength];
worldRay ← TransformRay[cameraRay, cameraWRTWorld]; -- allocates ray from pool
topColor ← ColorCast[[midTopX, top], worldRay, tree, lightSources, camera];
ReturnRayToPool[worldRay];
cameraRay.basePt ← [midTopX, bottom, 0];cameraRay.direction ← [midTopX, bottom, focalLength];
worldRay ← TransformRay[cameraRay, cameraWRTWorld]; -- allocates ray from pool
bottomColor ← ColorCast[[midTopX, bottom], worldRay, tree, lightSources, camera];
ReturnRayToPool[worldRay];
cameraRay.basePt ← [midTopX, midLeftY, 0];cameraRay.direction ← [midTopX, midLeftY, focalLength];
worldRay ← TransformRay[cameraRay, cameraWRTWorld]; -- allocates ray from pool
middleColor ← ColorCast[[midTopX, midLeftY], worldRay, tree, lightSources, camera];
ReturnRayToPool[worldRay];
color ← ColorAverage[ ColorAverage[ul, topColor, leftColor, middleColor],
ColorAverage[topColor, ur, middleColor, rightColor],
ColorAverage[leftColor, middleColor, dl, bottomColor],
ColorAverage[middleColor, rightColor, bottomColor, dr] ];
ReturnRayToPool[cameraRay];
}; -- end of CastMoreRays
Init:
PROC = {
Create a Classification Pool
globalPool ← NEW[PoolObj[globalPoolCount]];
FOR i:
NAT
IN[0..globalPoolCount)
DO
globalPool[i] ← NEW[ClassificationObj];
globalPool[i].surfaces ← NEW[SurfaceArrayObj];
ENDLOOP;
globalPoolPointer ← globalPoolCount;
Create a Ray Pool
globalRayPool ← NEW[RayPoolObj];
FOR i:
NAT
IN[1..globalRayPoolCount]
DO
globalRayPool[i] ← NEW[RayObj];
ENDLOOP;
globalRayPoolPointer ← globalRayPoolCount;
Create a Compact Pool
globalCompactPool ← NEW[CompactPoolObj];
FOR i:
NAT
IN[1..globalCompactPoolCount]
DO
globalCompactPool[i] ← NEW[CompactArrayObj];
ENDLOOP;
globalCompactPoolPointer ← globalCompactPoolCount;
};
NoOpNotifyOfProgress: PUBLIC NotifyOfProgressProc = {};
GetClassFromPool:
PUBLIC
PROC
RETURNS [class: Classification] = {
IF globalPoolPointer = 0 THEN AddAClass[];
class ← globalPool[globalPoolPointer - 1];
globalPoolPointer ← globalPoolPointer - 1;
};
ClassPoolEmpty: SIGNAL = CODE;
ReturnClassToPool:
PUBLIC
PROC [class: Classification] = {
IF globalPoolPointer = globalPool.maxClasses THEN SIGNAL ClassPoolFull;
globalPoolPointer ← globalPoolPointer + 1;
globalPool[globalPoolPointer - 1] ← class;
};
ClassPoolFull: SIGNAL = CODE;
NumberOfClassesInPool:
PUBLIC
PROC
RETURNS [count:
NAT] = {
count ← globalPoolPointer;
};
AddAClass:
PRIVATE
PROC = {
This scene contains sections complicated enough that the original allocation of classifications does not cover the most complicated rays. Add another classification to the pool.
newPool: Pool ← NEW[PoolObj[globalPool.maxClasses+1]];
IF globalPool.maxClasses > 50
THEN
{
-- there must be a leak in the classification system
MessageWindow.Append["Warning: More than 50 Classifications!!", TRUE];
MessageWindow.Blink[];
};
FOR i:
NAT
IN [0..globalPoolPointer)
DO
newPool[i] ← globalPool[i];
ENDLOOP;
globalPoolPointer ← globalPoolPointer + 1;
globalPool ← newPool;
globalPool[globalPoolPointer - 1] ← NEW[ClassificationObj];
globalPool[globalPoolPointer - 1].surfaces ← NEW[SurfaceArrayObj];
};
GetRayFromPool:
PUBLIC PROC
RETURNS [ray: Ray] = {
IF globalRayPoolPointer = 0 THEN SIGNAL RayPoolEmpty;
ray ← globalRayPool[globalRayPoolPointer];
globalRayPoolPointer ← globalRayPoolPointer -1;
};
RayPoolEmpty: SIGNAL = CODE;
ReturnRayToPool:
PUBLIC PROC [ray: Ray] = {
IF globalRayPoolPointer = globalRayPoolCount THEN SIGNAL RayPoolFull;
globalRayPoolPointer ← globalRayPoolPointer + 1;
globalRayPool[globalRayPoolPointer] ← ray;
};
RayPoolFull: SIGNAL = CODE;
GetCompactFromPool:
PROC
RETURNS [compact: CompactArray] = {
IF globalCompactPoolPointer = 0 THEN SIGNAL CompactPoolEmpty;
compact ← globalCompactPool[globalCompactPoolPointer];
globalCompactPoolPointer ← globalCompactPoolPointer -1;
};
CompactPoolEmpty: SIGNAL = CODE;
ReturnCompactToPool:
PROC [compact: CompactArray] = {
IF globalCompactPoolPointer = globalCompactPoolCount THEN SIGNAL CompactPoolFull;
globalCompactPoolPointer ← globalCompactPoolPointer + 1;
globalCompactPool[globalCompactPoolPointer] ← compact;
};
CompactPoolFull: SIGNAL = CODE;
MakeClassAMiss:
PUBLIC
PROC [class: Classification] = {
class.count ← 0;
class.classifs[1] ← FALSE;
};
Init[];